Biomaterial Database

Cell volume regulation in rat thin ascending limb of Henle's loop. 1992

L F Onuchic, and I R Arenstein, and A G Lopes

Department of Physiology, Faculdade de Medicina, Universidade de São Paulo, Brazil.

Thin ascending limb cells of Henle's loop from Wistar rats were studied with in vitro microperfusion and video-optical techniques to investigate their ability in regulating cell volume during osmotic shock and to identify mechanisms of ion transport involved in the process. These cells showed a clear volume regulatory decrease (VRD) response in hyposmotic medium, but no volume regulatory increase in hyperosmotic medium. The presence of barium in the bath abolished VRD. Removal of K+ from bath and perfusate also inhibited the VRD response. Reintroduction of K+ in hyposmotic conditions reestablished cell volume regulation. Introduction of anthracene-9-COOH to the basolateral medium blocked cell volume regulatory response. Cl- removal from perfusate and bath solutions also inhibited VRD, probably because of a significant intracellular Cl- depletion. Exposure of cells to ethylene glycol-bis(beta-aminoethyl ether)-N,N,N'N'-tetraacetic acid in perfusate and bath solutions reduced significantly Ca2+ concentration and impaired VRD. Reintroduction of Ca2+ in hyposmotic conditions restored volume regulation. The presence of ouabain in basolateral medium also inhibited VRD. These data suggest that the following mechanisms in the basolateral membrane are involved in VRD response: K+ and Cl- conductive pathways, which might be Ca2+ dependent for activation, and an Na(+)-K(+)-adenosinetriphosphatase.

UI	MeSH Term	Description	Entries
D008138	Loop of Henle	The U-shaped portion of the renal tubule in the KIDNEY MEDULLA, consisting of a descending limb and an ascending limb. It is situated between the PROXIMAL KIDNEY TUBULE and the DISTAL KIDNEY TUBULE.	Ascending Limb of Loop of Henle,Descending Limb of Loop of Henle,Henle Loop
D009994	Osmolar Concentration	The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.	Ionic Strength,Osmolality,Osmolarity,Concentration, Osmolar,Concentrations, Osmolar,Ionic Strengths,Osmolalities,Osmolar Concentrations,Osmolarities,Strength, Ionic,Strengths, Ionic
D009995	Osmosis	Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane.	Osmoses
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D003470	Culture Media	Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.	Media, Culture
D004533	Egtazic Acid	A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.	EGTA,Ethylene Glycol Tetraacetic Acid,EGATA,Egtazic Acid Disodium Salt,Egtazic Acid Potassium Salt,Egtazic Acid Sodium Salt,Ethylene Glycol Bis(2-aminoethyl ether)tetraacetic Acid,Ethylenebis(oxyethylenenitrile)tetraacetic Acid,GEDTA,Glycoletherdiamine-N,N,N',N'-tetraacetic Acid,Magnesium-EGTA,Tetrasodium EGTA,Acid, Egtazic,EGTA, Tetrasodium,Magnesium EGTA
D005942	Gluconates	Derivatives of gluconic acid (the structural formula HOCH2(CHOH)4COOH), including its salts and esters.	Copper Gluconate,Gluconate, Copper
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000873	Anthracenes	A group of compounds with three aromatic rings joined in linear arrangement.